FIELD OF INVENTION
[0001] The present invention is directed primarily to a novel route or process for preparing the emollient ester isodecyl oleate by esterification of branched decanol. This improved route claims an environmental friendly, zero discharge process coupled with efficient energy conservation.
BACKGROUND AND PRIOR ART
[0002] Wax esters are a significant group of chemical compounds. Esters of fatty acids are used as oil phase in many of the cosmetic formulations. Most of such esters are prepared by the esterification of carboxylic acid and fatty acids using acid catalysts. These processes involve high temperatures of reaction, use of unsafe solvents and longer duration of reaction.
[0003] Lately processes based on the use of biocatalysts have been used. Biocatalytic processes have gentle reaction conditions and relatively lower, temperatures, mostly less than 60°C. A greater advantage of enzymatic process is the specificity of the enzymes minimizing the untoward byproducts. Immobilized enzymes have further advantage of reuse for a number of cycles as the case may be.
[0004] Enzyme recycles stipulate minimum agitation or mechanical forces which may cause disintegration of the matrix, particle size reduction and poor recovery. The granular enzymes can become dusty fine powder which cannot be easily filtered out

after the cycle. A further condition for maximum enzyme recycles is the reduction in the reaction temperature to as low as possible and a pH as close to neutral as possible. [0005] During a typical esterification reaction or preparation of isodecyl oleate, a packed column of enzyme is used which consumes more reaction time.
[0006] Therefore there is still a need for a process for solvent-free, preparation of emollient ester isodecyl oleate, which permits high conversion rates with short reaction hours and concurrently more number of reuses of biocatalyst.
OBJECTS OF THE INVENTION
[0007] Some of the objects of the present disclosure are described herein below: [0008] A main object of the present invention is to provide a process for solvent-free,
preparation of isodecyl oleate, proceeding from the branched decanol and a
monosaturated fatty acid, which permits high conversion rates with short reaction
hours and concurrently more number of reuses of biocatalyst.
[0009] Another object of the present invention is to provide a reactor design in which
the mixing of one of the reactants is controlled and continuous and the discharge of
the water of reaction is achieved through introduction of vacuum.
[00010] Still another object of the present invention is to provide a process for
preparing an emollient ester, which is isodecyl oleate using said reactor design.
[00011] The other objects and advantages of the present invention will be apparent
from the following description when read in conjunction with the accompanying

drawings, which are incorporated for illustration of preferred embodiments of the present invention and are not intended to limit the scope thereof.
SUMMARY OF THE INVENTION
[00012] In view of the foregoing, the embodiment herein provides a process for preparation of the isodecyl oleate by esterification of branched decanol. According to an embodiment, a process for preparation of the isodecyl oleate comprising of continuous and controlled addition of a monosaturated omega fatty acid with branched decanol and an enzymatic catalyst into a reaction vessel and to form a reaction mixture, heating the reaction mixture in the reaction vessel at a pre-determined temperature, maintaining a vacuum pressure in the reaction vessel and continuously mixing the reaction mixture in the reaction vessel to remove water as vapor thereby achieving enzymatic esterification of the branched decanol to form the isodecyl oleate. According to an embodiment, the predetermined temperature is in the range of 45° C to 50° C.
[00013] According to an embodiment, the enzymatic catalyst is lipase. The lipase is selected from a group comprises of thermomyces lanuginosus, or Rhizomucor mehei. The enzymatic catalyst is immobilized on a non-compressible silica gel carrier or a resin carrier. [00014] According to an embodiment, the enzymatic esterification is achieved at a

rate of 95%.
[00015] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying examples. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
DETAILED DESCRIPTION OF EMBODIMENTS
[00016] The examples which follow are intended to illustrate the present invention in detail, without restricting the scope of protection, which is evident from the description and the claims. The process according to the invention will be described by way of example hereinafter. When documents are cited in the context of the present description, their content shall be incorporated fully into the disclosure-content of the present invention. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable

those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein. [00017] As mentioned above, there is a need for a process for preparing wax esters or emollient ester isodecyl oleate by esterification of branched decanol. The
5 embodiments herein achieve this through a process which results in solvent-free,
enzymatic preparation of isodecyl oleate, proceeding from the branched decanol and a monosaturated fatty acid, and permits high conversion rates with short reaction hours and concurrently more number of reuses. [00018] According to an embodiment, a process for preparation of the isodecyl oleate
0 comprising of continuous and controlled addition of a monosaturated omega fatty
acid with branched decanol and an enzymatic catalyst into a reaction vessel and to form a reaction mixture, heating the reaction mixture in the reaction vessel at a pre-determined temperature, maintaining a vacuum pressure in the reaction vessel and continuously mixing the reaction mixture in the reaction vessel to remove water as
5 vapor thereby achieving enzymatic esterification of the branched decanol to form said
isodecyl oleate. According to an embodiment, the predetermined temperature is in the range of 45° C. to 50° C.
[00019] According to an embodiment, the enzymatic catalyst is lipase. The catalysts used in accordance with the invention may be those whose mean particle size is such
0 that the catalyst remain suspended in the reaction mixture under mild stirring, i.e. are

larger than 0.5 um, preferably larger than 5um, more preferably larger than 10 um, especially larger than 25 um.
[00020] The enzymatic catalyst is immobilized on a non-compressible silica gel carrier or a resin carrier. To produce the immobilized enzymes, it is possible to use whole cells, resting cells, purified enzymes or cell extracts which comprise the enzymes in question or mixtures thereof. Preference is given to using hydrolytic enzymes, preferably lipases. The lipase is selected from a group comprises of thermomyces lanuginosus, or Rhizomucor mehei.
[00021] According to an embodiment, the enzymatic esterification is achieved at a rate of 95%.
[00022] The process according to the invention minimizes the pH stress induced by the acid reactant (monosaturated omega fatty acid), on the catalyst. This is a fundamental prerequisite for reusability and efficiency of the catalyst.
[00023] Lipases (EC Number 3.1.1.3) are one of the most commonly used classes of enzymes in biocatalysis. The reaction reverses under anhydrous conditions and the enzymes are able to synthesize new molecules by esterification, alcoholysis and transesterification. All reactions can be performed with high regio and enantioselectivity under mild reaction conditions. Lipases have been used on a variety of substrates and show very broad substrate specificity due to the ubiquity in nature

and the heterogeneity of lipases from different sources.
MATERIAL AND METHODS EMBODIMENTS
[00024] Novozym® 40086 (9001 62 1) brown immobilized granulate.
[00025] Isodecanol: Exxal TM10 from Exxon Mobil, Purity 99%.
[00026] Oleic acid: KORTACID 1811from Pacific Oleo; Fatty acid composition: C14
and below: 3% Max, C16: 6% Max, C18: 2%Max, C18:1: 78% Min, C18:2 13%
Max, C18:3 0.5% Max, Others 1.5% Max.
Example method for determination of Acid Value
[00027] In the biotransformation reaction (Esterification) we need an in process check which is determined easily to find out the progress of the reaction as well as to check whether the reaction is completed or not. Acid value indicates the residual oleic acid in the mixture. The acid value less than 1 signifies almost all of the oleic acid is consumed and the reaction is completed.
[00028] Acid Value is the number of mg of potassium hydroxide required to neutralize the free acids in 1.0 g of the substance. Dissolve 10.0 g of the substance (isodecyl oleate), accurately weighed, in 50 mL of a mixture of equal volumes of alcohol and petroleum ether (which has been neutralized to phenolphthalein with 0.1 N sodium hydroxide, unless otherwise specified) contained in a flask. Add 1 mL of phenolphthalein TS, and titrate with 0.1 N sodium hydroxide VS until the solution remains faintly pink after shaking for 30 s. Calculate the volume of 0.1 N alkali required to neutralize 10.0 g of sample (isodecyl oleate). [00029] Calculate the Acid Value:

(56.11 x V) x (N/W) V = volume (mL)
N = normality of the sodium hydroxide solution W = weight of the sample taken (g)
Example method for determination of hydroxyl value
[00030] As acid value indicates the residual oleic acid, hydroxyl value indicates the residual alcohol i.e branched decanol i.e, isodecanol.
[00031] Weigh 10.0 g sample (isodecyl decanol) in a tared glass stoppered 250 mL conical flask and add 5.0 mL of Pyridine-Acetic anhydride reagent. Transfer 5.0 mL of Pyridine-Acetic anhydride reagent to a second glass stoppered 250 mL conical flask and fit both flasks with suitable glass- jointed reflux condensers, heat on a steam bath for 3 hours, add 10 mL of water through each condenser, and heat on the steam bath for 10minutes more. Cool, and to each add 25 mL of butyl alcohol, previously neutralized to phenolphthalein indicator with 0.5 N alcoholic potassium hydroxide, by pouring 15 mL through each condenser and, after removing the condensers, washing the sides of both flasks with the remaining 10-mL portions. To each flask add 1 mL of phenolphthalein indicator, and titrate with 0.5 N alcoholic potassium hydroxide VS. Calculate the hydroxyl value by the formula: 56.11 X (B –T) X N /W + Acid Value. [00032] In which 56.11= the molecular weight of potassium hydroxide, B = is the volume of potassium hydroxide consumed by blank, T = is the volume of potassium

hydroxide consumed by sample, N= Normality of the alcoholic potassium hydroxide solution, W= Weight of the sample (isodecyl oleate) taken in g.
Examples of the process for preparing isodecyl oleate
[00033] The invention further described by the following examples which further illustrates the invention, and is not intended, nor should they be interpreted to limit the scope of the invention.
Example 1-Packed Column Process (Prior art)
[00034] 578.83g of oleic acid and 351.14g of isodecanol were mixed under stirring in a three neck flask and 0.93g of the biocatalyst was packed in a glass column. The reaction mixture was heated to 450C and was passed through the enzyme bed at a specific flow rate using a peristaltic pump which was in turn passed through molecular sieves packed in another column to trap the water of reaction. The course of the reaction was monitored for 15 hrs by estimation of acid value (Table1). The residual alcohol was estimated by hydroxyl value estimation which was found to be 5.1mg KOH/g. Table 1 shows acid value and the reaction time according to packed column process.

Example 2-Process according to the present invention
[00035] Example- 2 is a novel dynamic reaction set up design where enzyme is stirred
in the reactor instead of packing in the column and the reactant is added from a
dropping funnel.
[00036] 351.14g of isodecanol was heated to 450C in a three neck flask and 0.93g of
the biocatalyst was added under stirring. 578.83g of oleic acid was added
continuously at a constant rate using a dropping funnel. The water of reaction formed
was removed by applying vacuum and the water was distilled out. The reaction was
monitored for 10 hrs in terms of acid value (Table 2). The hydroxyl value was found
to be 2.77mgKOH/g.

[00037] It is clearly evident from Table 2 that the scalable reaction set up of the present invention reduces the log hrs i.e, the reaction time when compared to prior art process.
[00038] The claimed process permits high conversion rates with short reaction hours and concurrently more number of reuses of biocatalyst (recycling of biocatalyst). Several batches of example 2 were carried out reusing the enzymatic catalyst and the percentage conversions were calculated according to the yield of isodecyl oleate and the number of cycles for reuse was determined (Table 3).

[00039] Table 3 illustrates conversion rate, reaction time corresponding to number of reuse of biocatalyst. The enzyme which was used in the first batch has been recycled for 10 times i.e 10 batches. Up to 5 cycles the biotransformation (Esterification) conversion rate % remains the same. Further the conversion rate loses efficiency little by little. Therefore, the recycling of biocatalysts signifies the economic advantage. [00040] A main advantage of the present invention is that the process results in solvent-free, preparation of isodecyl oleate, proceeding from the branched decanol and a monosaturated fatty acid,
[00041] Another advantage of the present invention is that the process permits high conversion rates with short reaction hours and concurrently more number of reuses of biocatalyst.

[00042] Still another advantage of the present invention is that the process provides a reactor design in which the mixing of one of the reactants is controlled and continuous and the discharge of the water of reaction is achieved through introduction of vacuum.
[00043] Yet another advantage of the present invention is that the process provides an emollient ester, which is isodecyl oleate using said reactor design.
[00044] Another advantage of the present invention is that the process minimizes the pH stress induced by the acid reactant (monosaturated omega fatty acid), on the catalyst.
[00045] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and therefore, such adaptations and modifications should are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.

1. A process for preparation of isodecyl oleate comprising of :
continuous and controlled addition of a monosaturated omega fatty acid with branched decanol and an enzymatic catalyst into a reaction vessel and to form a reaction mixture; heating the reaction mixture in the reaction vessel at a pre-determined temperature;
maintaining a vacuum pressure in the reaction vessel and continuously mixing the reaction mixture in the reaction vessel to remove water as vapor thereby achieving enzymatic esterification of the branched decanol to form the isodecyl oleate.
2. The process as claimed in claim 1, wherein said enzymatic catalyst is lipase.
3. The process as claimed in claim 2, wherein said lipase selected from a group
comprises of thermomyces lanuginosus, or Rhizomucor mehei.
4. The process as claimed in claim 3, wherein the enzymatic catalyst is
immobilized on a non-compressible silica gel carrier or a resin carrier.
5. The process as claimed in claim 1, wherein said predetermined temperature is
in a range of 45° C. to 50° C.
6. The process as claimed in claim 1, wherein the enzymatic esterification is
achieved at a rate of 95%.